Establishing Connections With Chargers In Multi-Charger Wireless Power Delivery Environments

ABSTRACT

Techniques for establishing RF power connections with wireless power transmission systems in multi-wireless power transmission system environments are described herein. More specifically, the techniques describe a method for establishing a connection with an optimal wireless power transmission system when multiple wireless power transmission systems are within range.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/092,026 titled “ESTABLISHING CONNECTIONS WITH CHARGERS INMULTI-CHARGER WIRELESS POWER DELIVERY ENVIRONMENTS” filed on Apr. 6,2016, now allowed; which claims priority to and benefit from U.S.Provisional Patent Application No. 62/146,233 titled “SYSTEMS ANDMETHODS FOR WIRELESS CHARGING” filed on Apr. 10, 2015, both of which areexpressly incorporated by reference herein.

TECHNICAL FIELD

The technology described herein relates generally to the field ofwireless power transmission and, more specifically, to techniques forestablishing wireless power radio frequency (RF) power connections withwireless power transmission systems (or chargers) in multi-wirelesspower transmission system environments.

BACKGROUND

Many portable electronic devices are powered by batteries. Rechargeablebatteries are often used to avoid the cost of replacing conventionaldry-cell batteries and to conserve precious resources. However,recharging batteries with conventional rechargeable battery chargersrequires access to an alternating current (AC) power outlet, which issometimes not available or not convenient. It is therefore desirable toderive power for mobile portable electronics via electromagneticradiation. Some systems for wireless charging via electromagneticradiation have been disclosed.

Some wireless power delivery environments include multiple wirelesscharging systems that are each capable of providing wireless power towireless devices within range. In many cases, the wireless powerdelivery ranges of the wireless charging systems overlap resulting inmore than one charger that is capable of providing a wireless devicewith power. In such cases, the multi-charger environments tend to resultin unbalanced pairings between wireless devices and the wireless powertransmission systems. That is, some wireless charging systems might beunder-utilized while others provide power to a maximum number ofallowable wireless devices.

Accordingly, a need exists for technology that overcomes the problemdemonstrated above, as well as one that provides additional benefits.The examples provided herein of some prior or related systems and theirassociated limitations are intended to be illustrative and notexclusive. Other limitations of existing or prior systems will becomeapparent to those of skill in the art upon reading the followingDetailed Description.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present invention are illustrated by wayof example and not limitation in the figures of the accompanyingdrawings, in which like references indicate similar elements.

FIG. 1 depicts a block diagram including an example wireless powerdelivery environment illustrating wireless power delivery from one ormore wireless power transmission systems to various wireless deviceswithin the wireless power delivery environment in accordance with someembodiments.

FIG. 2 depicts a sequence diagram illustrating example operationsbetween a wireless power transmission system and a wireless receiverclient for commencing wireless power delivery in accordance with someembodiments.

FIG. 3 depicts a block diagram illustrating example components of awireless power transmission system in accordance with some embodiments.

FIG. 4 depicts a block diagram illustrating example components of awireless power receiver client in accordance with some embodiments.

FIGS. 5A and 5B depict diagrams illustrating an example multipathwireless power delivery environment in accordance with some embodiments.

FIG. 6 illustrates an example wireless power delivery environmentincluding multiple wireless power transmission systems and multiplepower receiver clients in accordance with some embodiments.

FIG. 7 is a flow diagram illustrating an example process forestablishing RF power connections with wireless power transmissionsystems in multi-wireless power transmission system environments inaccordance with some embodiments.

FIG. 8 is a flow diagram illustrating an example process for determiningwhether to accept a connection invitation from a wireless powertransmission system in accordance with some embodiments.

FIG. 9 is a flow diagram illustrating an example process of scoringwireless power transmission systems within range in accordance with someembodiments.

FIG. 10 is an example table illustrating various wireless powertransmission system selection criteria in accordance with someembodiments.

FIG. 11 is a flow diagram illustrating another example process forestablishing connections with continuous power delivery wirelesscharging systems in accordance with some embodiments.

FIG. 12 depicts a block diagram illustrating example components of arepresentative mobile device or tablet computer with one or morewireless power receiver clients in the form of a mobile (or smart) phoneor tablet computer device in accordance with some embodiments.

FIG. 13 depicts a diagrammatic representation of a machine, in theexample form, of a computer system within which a set of instructions,for causing the machine to perform any one or more of the methodologiesdiscussed herein, may be executed.

DETAILED DESCRIPTION

Techniques for establishing RF power connections with wireless powertransmission systems in multi-wireless power transmission system powerdelivery environments are described herein. More specifically, thetechniques describe a method for establishing a connection with anoptimal wireless power transmission system when multiple wireless powertransmission systems are within range.

The following description and drawings are illustrative and are not tobe construed as limiting. Numerous specific details are described toprovide a thorough understanding of the disclosure. However, in certaininstances, well-known or conventional details are not described in orderto avoid obscuring the description. References to one or an embodimentin the present disclosure can be, but not necessarily are, references tothe same embodiment; and, such references mean at least one of theembodiments.

Reference in this specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least one embodimentof the disclosure. The appearances of the phrase “in one embodiment” invarious places in the specification are not necessarily all referring tothe same embodiment, nor are separate or alternative embodimentsmutually exclusive of other embodiments. Moreover, various features aredescribed which may be exhibited by some embodiments and not by others.Similarly, various requirements are described which may be requirementsfor some embodiments but no other embodiments.

The terms used in this specification generally have their ordinarymeanings in the art, within the context of the disclosure, and in thespecific context where each term is used. Certain terms that are used todescribe the disclosure are discussed below, or elsewhere in thespecification, to provide additional guidance to the practitionerregarding the description of the disclosure. For convenience, certainterms may be highlighted, for example using italics and/or quotationmarks. The use of highlighting has no influence on the scope and meaningof a term; the scope and meaning of a term is the same, in the samecontext, whether or not it is highlighted. It will be appreciated thatsame thing can be said in more than one way.

Consequently, alternative language and synonyms may be used for any oneor more of the terms discussed herein, nor is any special significanceto be placed upon whether or not a term is elaborated or discussedherein. Synonyms for certain terms are provided. A recital of one ormore synonyms does not exclude the use of other synonyms. The use ofexamples anywhere in this specification, including examples of any termsdiscussed herein, is illustrative only, and is not intended to furtherlimit the scope and meaning of the disclosure or of any exemplifiedterm. Likewise, the disclosure is not limited to various embodimentsgiven in this specification.

Without intent to further limit the scope of the disclosure, examples ofinstruments, apparatus, methods and their related results according tothe embodiments of the present disclosure are given below. Note thattitles or subtitles may be used in the examples for convenience of areader, which in no way should limit the scope of the disclosure. Unlessotherwise defined, all technical and scientific terms used herein havethe same meaning as commonly understood by one of ordinary skill in theart to which this disclosure pertains. In the case of conflict, thepresent document, including definitions, will control.

I. Wireless Power Transmission System Overview/Architecture

FIG. 1 depicts a block diagram including an example wireless powerdelivery environment 100 illustrating wireless power delivery from oneor more wireless power transmission systems (WPTS) 101 a-n (alsoreferred to as “wireless power delivery systems”, “antenna arraysystems” and “wireless chargers”) to various wireless devices 102 a-nwithin the wireless power delivery environment 100, according to someembodiments. More specifically, FIG. 1 illustrates an example wirelesspower delivery environment 100 in which wireless power and/or data canbe delivered to available wireless devices 102 a-102 n having one ormore wireless power receiver clients 103 a-103 n (also referred toherein as “clients” and “wireless power receivers”). The wireless powerreceiver clients are configured to receive and process wireless powerfrom one or more wireless power transmission systems 101 a-101 n.Components of an example wireless power receiver client 103 are shownand discussed in greater detail with reference to FIG. 4.

As shown in the example of FIG. 1, the wireless devices 102 a-102 ninclude mobile phone devices and a wireless game controller. However,the wireless devices 102 a-102 n can be any device or system that needspower and is capable of receiving wireless power via one or moreintegrated power receiver clients 103 a-103 n. As discussed herein, theone or more integrated power receiver clients receive and process powerfrom one or more wireless power transmission systems 101 a-101 n andprovide the power to the wireless devices 102 a-102 n (or internalbatteries of the wireless devices) for operation thereof.

Each wireless power transmission system 101 can include multipleantennas 104 a-n, e.g., an antenna array including hundreds or thousandsof antennas, which are capable of delivering wireless power to wirelessdevices 102. In some embodiments, the antennas are adaptively-phasedradio frequency (RF) antennas. The wireless power transmission system101 is capable of determining the appropriate phases with which todeliver a coherent power transmission signal to the power receiverclients 103. The array is configured to emit a signal (e.g., continuouswave or pulsed power transmission signal) from multiple antennas at aspecific phase relative to each other. It is appreciated that use of theterm “array” does not necessarily limit the antenna array to anyspecific array structure. That is, the antenna array does not need to bestructured in a specific “array” form or geometry. Furthermore, as usedherein he term “array” or “array system” may be used include related andperipheral circuitry for signal generation, reception and transmission,such as radios, digital logic and modems. In some embodiments, thewireless power transmission system 101 can have an embedded Wi-Fi hubfor data communications via one or more antennas or transceivers.

The wireless devices 102 can include one or more receive power clients103. As illustrated in the example of FIG. 1, power delivery antennas104 a-104 n are shown. The power delivery antennas 104 a are configuredto provide delivery of wireless radio frequency power in the wirelesspower delivery environment. In some embodiments, one or more of thepower delivery antennas 104 a-104 n can alternatively or additionally beconfigured for data communications in addition to or in lieu of wirelesspower delivery. The one or more data communication antennas areconfigured to send data communications to and receive datacommunications from the power receiver clients 103 a-103 n and/or thewireless devices 102 a-102 n. In some embodiments, the datacommunication antennas can communicate via Bluetooth, Wi-Fi, ZigBee,etc. Other data communication protocols are also possible.

Each power receiver client 103 a-103 n includes one or more antennas(not shown) for receiving signals from the wireless power transmissionsystems 101 a-101 n. Likewise, each wireless power transmission system101 a-101 n includes an antenna array having one or more antennas and/orsets of antennas capable of emitting continuous wave or discrete (pulse)signals at specific phases relative to each other. As discussed above,each the wireless power transmission systems 101 a-101 n is capable ofdetermining the appropriate phases for delivering the coherent signalsto the power receiver clients 102 a-102 n. For example, in someembodiments, coherent signals can be determined by computing the complexconjugate of a received beacon (or calibration) signal at each antennaof the array such that the coherent signal is phased for deliveringpower to the particular power receiver client that transmitted thebeacon (or calibration) signal.

Although not illustrated, each component of the environment, e.g.,wireless device, wireless power transmission system, etc., can includecontrol and synchronization mechanisms, e.g., a data communicationsynchronization module. The wireless power transmission systems 101a-101 n can be connected to a power source such as, for example, a poweroutlet or source connecting the wireless power transmission systems to astandard or primary alternating current (AC) power supply in a building.Alternatively, or additionally, one or more of the wireless powertransmission systems 101 a-101 n can be powered by a battery or viaother mechanisms, e.g., solar cells, etc.

The power receiver clients 102 a-102 n and/or the wireless powertransmission systems 101 a-101 n are configured to operate in amultipath wireless power delivery environment. That is, the powerreceiver clients 102 a-102 n and the wireless power transmission systems101 a-101 n are configured to utilize reflective objects 106 such as,for example, walls or other RF reflective obstructions within range totransmit beacon (or calibration) signals and/or receive wireless powerand/or data within the wireless power delivery environment. Thereflective objects 106 can be utilized for multi-directional signalcommunication regardless of whether a blocking object is in the line ofsight between the wireless power transmission system and the powerreceiver client.

As described herein, each wireless device 102 a-102 n can be any systemand/or device, and/or any combination of devices/systems that canestablish a connection with another device, a server and/or othersystems within the example environment 100. In some embodiments, thewireless devices 102 a-102 n include displays or other outputfunctionalities to present data to a user and/or input functionalitiesto receive data from the user. By way of example, a wireless device 102can be, but is not limited to, a video game controller, a serverdesktop, a desktop computer, a computer cluster, a mobile computingdevice such as a notebook, a laptop computer, a handheld computer, amobile phone, a smart phone, a PDA, a Blackberry device, a Treo, and/oran iPhone, etc. By way of example and not limitation, the wirelessdevice 102 can also be any wearable device such as watches, necklaces,rings or even devices embedded on or within the customer. Other examplesof a wireless device 102 include, but are not limited to, safety sensors(e.g., fire or carbon monoxide), electric toothbrushes, electronic doorlock/handles, electric light switch controller, electric shavers, etc.

Although not illustrated in the example of FIG. 1, the wireless powertransmission system 101 and the power receiver clients 103 a-103 n caneach include a data communication module for communication via a datachannel. Alternatively, or additionally, the power receiver clients 103a-103 n can direct the wireless devices 102.1-102.n to communicate withthe wireless power transmission system via existing data communicationsmodules. In some embodiments the beacon signal, which is primarilyreferred to herein as a continuous waveform, can alternatively oradditionally take the form of a modulated signal.

FIG. 2 is a sequence diagram 200 illustrating example operations betweena wireless power delivery system (e.g., WPTS 101) and a wireless powerreceiver client (e.g., wireless power receiver client 103) forestablishing wireless power delivery in a multipath wireless powerdelivery, according to an embodiment. Initially, communication isestablished between the wireless power transmission system 101 and thepower receiver client 103. The initial communication can be, forexample, a data communication link that is established via one or moreantennas 104 of the wireless power transmission system 101. Asdiscussed, in some embodiments, one or more of the antennas 104 a-104 ncan be data antennas, wireless power transmission antennas, ordual-purpose data/power antennas. Various information can be exchangedbetween the wireless power transmission system 101 and the wirelesspower receiver client 103 over this data communication channel. Forexample, wireless power signaling can be time sliced among variousclients in a wireless power delivery environment. In such cases, thewireless power transmission system 101 can send beacon scheduleinformation, e.g., Beacon Beat Schedule (BBS) cycle, power cycleinformation, etc., so that the wireless power receiver client 103 knowswhen to transmit (broadcast) its beacon signals and when to listen forpower, etc.

Continuing with the example of FIG. 2, the wireless power transmissionsystem 101 selects one or more wireless power receiver clients forreceiving power and sends the beacon schedule information to the selectpower receiver clients 103. The wireless power transmission system 101can also send power transmission scheduling information so that thepower receiver client 103 knows when to expect (e.g., a window of time)wireless power from the wireless power transmission system. The powerreceiver client 103 then generates a beacon (or calibration) signal andbroadcasts the beacon during an assigned beacon transmission window (ortime slice) indicated by the beacon schedule information, e.g., BeaconBeat Schedule (BBS) cycle. As discussed herein, the wireless powerreceiver client 103 include one or more antennas (or transceivers) whichhave a radiation and reception pattern in three-dimensional spaceproximate to the wireless device 102 in which the power receiver client103 is embedded.

The wireless power transmission system 101 receives the beacon from thepower receiver client 103 and detects and/or otherwise measures thephase (or direction) from which the beacon signal is received atmultiple antennas. The wireless power transmission system 101 thendelivers wireless power to the power receiver client 103 from themultiple antennas 103 based on the detected or measured phase (ordirection) of the received beacon at each of the corresponding antennas.In some embodiments, the wireless power transmission system 101determines the complex conjugate of the measured phase of the beacon anduses the complex conjugate to determine a transmit phase that configuresthe antennas for delivering and/or otherwise directing wireless power tothe power receiver client 103 via the same path over which the beaconsignal was received from the power receiver client 103.

In some embodiments, the wireless power transmission system 101 includesmany antennas; one or more of which are used to deliver power to thepower receiver client 103. The wireless power transmission system 101can detect and/or otherwise determine or measure phases at which thebeacon signals are received at each antenna. The large number ofantennas may result in different phases of the beacon signal beingreceived at each antenna of the wireless power transmission system 101.As discussed above, the wireless power transmission system 101 candetermine the complex conjugate of the beacon signals received at eachantenna. Using the complex conjugates, one or more antennas may emit asignal that takes into account the effects of the large number ofantennas in the wireless power transmission system 101. In other words,the wireless power transmission system 101 can emit a wireless powertransmission signal from the one or more antennas in such a way as tocreate an aggregate signal from the one or more of the antennas thatapproximately recreates the waveform of the beacon in the oppositedirection. Said another way, the wireless power transmission system 101can deliver wireless RF power to the client device via the same pathsover which the beacon signal is received at the wireless powertransmission system 101. These paths can utilize reflective objects 106within the environment. Additionally, the wireless power transmissionsignals can be simultaneously transmitted from the wireless powertransmission system 101 such that the wireless power transmissionsignals collectively match the antenna radiation and reception patternof the client device in a three-dimensional (3D) space proximate to theclient device.

As shown, the beacon (or calibration) signals can be periodicallytransmitted by power receiver clients 103 within the power deliveryenvironment according to, for example, the BBS, so that the wirelesspower transmission system 101 can maintain knowledge and/or otherwisetrack the location of the power receiver clients 103 in the wirelesspower delivery environment. Furthermore, as discussed herein, wirelesspower can be delivered in power cycles defined by power scheduleinformation. A more detailed example of the signaling required tocommence wireless power delivery is described now with reference to FIG.3.

FIG. 3 is a block diagram illustrating example components of a wirelesspower transmission system 300, in accordance with an embodiment. Asillustrated in the example of FIG. 3, the wireless charger 300 includesa master bus controller (MBC) board and multiple mezzanine boards thatcollectively comprise the antenna array. The MBC includes control logic310, an external data interface (I/F) 315, an external power interface(I/F) 320, a communication block 330 and proxy 340. The mezzanine (orantenna array boards 350) each include multiple antennas 360 a-360 n.Some or all of the components can be omitted in some embodiments.Additional components are also possible.

The control logic 310 is configured to provide control and intelligenceto the array components. The control logic 310 may comprise one or moreprocessors, FPGAs, memory units, etc., and direct and control thevarious data and power communications. The communication block 330 candirect data communications on a data carrier frequency, such as the basesignal clock for clock synchronization. The data communications can beBluetooth, Wi-Fi, ZigBee, etc., including combinations or variationsthereof. Likewise, the proxy 340 can communicate with clients via datacommunications as discussed herein. The data communications can beBluetooth, Wi-Fi, ZigBee, etc.

In some embodiments, the control logic 310 can also facilitate and/orotherwise enable data aggregation for Internet of Things (IoT) devices.In some embodiments, wireless power receiver clients can access, trackand/or otherwise obtain IoT information about the device in which thewireless power receiver client is embedded and provide that IoTinformation to the wireless power transmission system 300 over a dataconnection. This IoT information can be provided to via an external datainterface 315 to a central or cloud-based system (not shown) where thedata can be aggregated, processed, etc. For example, the central systemcan process the data to identify various trends across geographies,wireless power transmission systems, environments, devices, etc. In someembodiments, the aggregated data and or the trend data can be used toimprove operation of the devices via remote updates, etc. Alternatively,or additionally, in some embodiments, the aggregated data can beprovided to third party data consumers. In this manner, the wirelesspower transmission system acts as a Gateway or Enabler for the IoTs. Byway of example and not limitation, the IoT information can includecapabilities of the device in which the wireless power receiver clientis embedded, usage information of the device, power levels of thedevice, information obtained by the device or the wireless powerreceiver client itself, e.g., via sensors, etc.

The external power interface 320 is configured to receive external powerand provide the power to various components. In some embodiments, theexternal power interface 320 may be configured to receive a standardexternal 24 Volt power supply. Alternative configurations are alsopossible.

An example of a system power cycle is now described. In this example,the master bus controller (MBC), which controls the wireless powertransmission system, first receives power from a power source and isactivated. The MBC then activates the proxy antenna elements on thewireless power transmission system and the proxy antenna elements entera default “discovery” mode to identify available wireless receiverclients within range of the wireless power transmission system. When aclient is found, the antenna elements on the wireless power transmissionsystem power on, enumerate, and (optionally) calibrate.

The MBC then generates beacon transmission scheduling information andpower transmission scheduling information during a scheduling process.The scheduling process includes selection of power receiver clients. Forexample, the MBC can select power receiver clients for powertransmission and generate a Beacon Beat Schedule (BBS) cycle and a PowerSchedule (PS) for the selected wireless power receiver clients. Asdiscussed herein, the power receiver clients can be selected based ontheir corresponding properties and/or requirements.

In some embodiments, the MBC can also identify and/or otherwise selectavailable clients that will have their status queried in the ClientQuery Table (CQT). Clients that are placed in the CQT are those on“standby”, e.g., not receiving a charge. The BBS and PS are calculatedbased on vital information about the clients such as, for example,battery status, current activity/usage, how much longer the client hasuntil it runs out of power, priority in terms of usage, etc.

The Proxy AE broadcasts the BBS to all clients. As discussed herein, theBBS indicates when each client should send a beacon. Likewise, the PSindicates when and to which clients the array should send power to andwhen clients should listen for wireless power. Each client startsbroadcasting its beacon and receiving power from the array per the BBSand PS. The Proxy can concurrently query the Client Query Table to checkthe status of other available clients. In some embodiments, a client canonly exist in the BBS or the CQT (e.g., waitlist), but not in both. Alimited number of clients can be served on the BBS and PS (e.g., 32).Likewise, the CQT may also be limited to a number of clients (e.g., 32).Thus, for example, if more than 64 clients are within range of thewireless power transmission system, some of those clients would not beactive in either the BBS or CQT. The information collected in theprevious step continuously and/or periodically updates the BBS cycleand/or the PS.

FIG. 4 is a block diagram illustrating example components of a wirelesspower receiver client, in accordance with some embodiments. Asillustrated in the example of FIG. 4, the receiver 400 includes controllogic 410, battery 420, an IoT control module 425, communication block430 and associated antenna 470, power meter 440, rectifier 450, acombiner 455, beacon signal generator 460, beacon coding unit 462 and anassociated antenna 480, and switch 465 connecting the rectifier 450 orthe beacon signal generator 460 to one or more associated antennas 490a-n. Some or all of the components can be omitted in some embodiments.For example, in some embodiments, the wireless power receiver clientdoes not include its own antennas but instead utilizes and/or otherwiseshares one or more antennas (e.g., Wi-Fi antenna) of the wireless devicein which the wireless power receiver client is embedded. Moreover, insome embodiments, the wireless power receiver client may include asingle antenna that provides data transmission functionality as well aspower/data reception functionality. Additional components are alsopossible.

A combiner 455 receives and combines the received power transmissionsignals from the power transmitter in the event that the receiver 400has more than one antenna. The combiner can be any combiner or dividercircuit that is configured to achieve isolation between the output portswhile maintaining a matched condition. For example, the combiner 455 canbe a Wilkinson Power Divider circuit. The rectifier 450 receives thecombined power transmission signal from the combiner 455, if present,which is fed through the power meter 440 to the battery 420 forcharging. The power meter 440 can measure the received power signalstrength and provides the control logic 410 with this measurement.

The control logic 410 can receive the battery power level from thebattery 420 itself. The control logic 410 may also transmit/receive viathe communication block 430 a data signal on a data carrier frequency,such as the base signal clock for clock synchronization. The beaconsignal generator 460 generates the beacon signal, or calibration signal,transmits the beacon signal using either the antenna 480 or 490 afterthe beacon signal is encoded.

It may be noted that, although the battery 420 is shown for as chargedby and providing power to the receiver 400, the receiver may alsoreceive its power directly from the rectifier 450. This may be inaddition to the rectifier 450 providing charging current to the battery420, or in lieu of providing charging. Also, it may be noted that theuse of multiple antennas is one example of implementation and thestructure may be reduced to one shared antenna.

In some embodiments, the control logic 410 and/or the IoT control module425 can communicate with and/or otherwise derive IoT information fromthe device in which the wireless power receiver client 400 is embedded.Although not shown, in some embodiments, the wireless power receiverclient 400 can have one or more data connections (wired or wireless)with the device in which the wireless power receiver client 400 isembedded over which IoT information can be obtained. Alternatively, oradditionally, IoT information can be determined and/or inferred by thewireless power receiver client 400, e.g., via one or more sensors. Asdiscussed above, the IoT information can include, but is not limited to,information about the capabilities of the device in which the wirelesspower receiver client is embedded, usage information of the device inwhich the wireless power receiver client is embedded, power levels ofthe battery or batteries of the device in which the wireless powerreceiver client is embedded, and/or information obtained or inferred bythe device in which the wireless power receiver client is embedded orthe wireless power receiver client itself, e.g., via sensors, etc.

In some embodiments, a client identifier (ID) module 415 stores a clientID that can uniquely identify the power receiver client in a wirelesspower delivery environment. For example, the ID can be transmitted toone or more wireless power transmission systems when communication isestablished. In some embodiments, power receiver clients may also beable to receive and identify other power receiver clients in a wirelesspower delivery environment based on the client ID.

An optional motion sensor 495 can detect motion and signal the controllogic 410 to act accordingly. For example, when a device is receivingpower at high frequencies, e.g., above 500 MHz, its location may becomea hotspot of (incoming) radiation. Thus, when the device is on a person,e.g., embedded in a mobile device, the level of radiation may exceedacceptable radiation levels set by the Federal Communications Commission(FCC) or other medical/industrial authorities. To avoid any potentialradiation issue, the device may integrate motion detection mechanismssuch as accelerometers or equivalent mechanisms. Once the device detectsthat it is in motion, it may be assumed that it is being handled by auser, and would trigger a signal to the array either to stoptransmitting power to it, or to lower the received power to anacceptable fraction of the power. In cases where the device is used in amoving environment like a car, train or plane, the power might only betransmitted intermittently or at a reduced level unless the device isclose to losing all available power.

FIGS. 5A and 5B depict diagrams illustrating an example multipathwireless power delivery environment 500, according to some embodiments.The multipath wireless power delivery environment 500 includes a useroperating a wireless device 502 including one or more wireless powerreceiver clients 503. The wireless device 502 and the one or morewireless power receiver clients 503 can be wireless device 102 of FIG. 1and wireless power receiver client 103 of FIG. 1 or wireless powerreceiver client 400 of FIG. 4, respectively, although alternativeconfigurations are possible. Likewise, wireless power transmissionsystem 501 can be wireless power transmission system 101 FIG. 1 orwireless power transmission system 300 of FIG. 3, although alternativeconfigurations are possible. The multipath wireless power deliveryenvironment 500 includes reflective objects 506 and various absorptiveobjects, e.g., users, or humans, furniture, etc.

Wireless device 502 includes one or more antennas (or transceivers) thathave a radiation and reception pattern 510 in three-dimensional spaceproximate to the wireless device 102. The one or more antennas (ortransceivers) can be wholly or partially included as part of thewireless device 102 and/or the wireless power receiver client (notshown). For example, in some embodiments one or more antennas, e.g.,Wi-Fi, Bluetooth, etc. of the wireless device 502 can be utilized and/orotherwise shared for wireless power reception. As shown in the exampleof FIGS. 5A and 5B, the radiation and reception pattern 510 comprises alobe pattern with a primary lobe and multiple side lobes. Other patternsare also possible.

The wireless device 502 transmits a beacon (or calibration) signal overmultiple paths to the wireless power transmission system 501. Asdiscussed herein, the wireless device 502 transmits the beacon in thedirection of the radiation and reception pattern 510 such that thestrength of the received beacon signal by the wireless powertransmission system, e.g., RSSI, depends on the radiation and receptionpattern 510. For example, beacon signals are not transmitted where thereare nulls in the radiation and reception pattern 510 and beacon signalsare the strongest at the peaks in the radiation and reception pattern510, e.g., peak of the primary lobe. As shown in the example of FIG. 5A,the wireless device 502 transmits beacon signals over five paths P1-P5.Paths P4 and P5 are blocked by reflective and/or absorptive object 506.The wireless power transmission system 501 receives beacon signals ofincreasing strengths via paths P1-P3. The bolder lines indicate strongersignals. In some embodiments the beacon signals are directionallytransmitted in this manner to, for example, avoid unnecessary RF energyexposure to the user.

A fundamental property of antennas is that the receiving pattern(sensitivity as a function of direction) of an antenna when used forreceiving is identical to the far-field radiation pattern of the antennawhen used for transmitting. This is a consequence of the reciprocitytheorem in electromagnetics. As shown in the example of FIGS. 5A and 5B,the radiation and reception pattern 510 is a three-dimensional lobeshape. However, the radiation and reception pattern 510 can be anynumber of shapes depending on the type or types, e.g., horn antennas,simple vertical antenna, etc. used in the antenna design. For example,the radiation and reception pattern 510 can comprise various directivepatterns. Any number of different antenna radiation and receptionpatterns are possible for each of multiple client devices in a wirelesspower delivery environment.

Referring again to FIG. 5A, the wireless power transmission system 501receives the beacon (or calibration) signal via multiple paths P1-P3 atmultiple antennas or transceivers. As shown, paths P2 and P3 are directline of sight paths while path P1 is a non-line of sight path. Once thebeacon (or calibration) signal is received by the wireless powertransmission system 501, the power transmission system 501 processes thebeacon (or calibration) signal to determine one or more receivecharacteristics of the beacon signal at each of the multiple antennas.For example, among other operations, the wireless power transmissionsystem 501 can measure the phases at which the beacon signal is receivedat each of the multiple antennas or transceivers.

The wireless power transmission system 501 processes the one or morereceive characteristics of the beacon signal at each of the multipleantennas to determine or measure one or more wireless power transmitcharacteristics for each of the multiple RF transceivers based on theone or more receive characteristics of the beacon (or calibration)signal as measured at the corresponding antenna or transceiver. By wayof example and not limitation, the wireless power transmitcharacteristics can include phase settings for each antenna ortransceiver, transmission power settings, etc.

As discussed herein, the wireless power transmission system 501determines the wireless power transmit characteristics such that, oncethe antennas or transceivers are configured, the multiple antennas ortransceivers are operable to transit a wireless power signal thatmatches the client radiation and reception pattern in thethree-dimensional space proximate to the client device. FIG. 5Billustrates the wireless power transmission system 501 transmittingwireless power via paths P1-P3 to the wireless device 502.Advantageously, as discussed herein, the wireless power signal matchesthe client radiation and reception pattern 510 in the three-dimensionalspace proximate to the client device. Said another way, the wirelesspower transmission system will transmit the wireless power signals inthe direction in which the wireless power receiver has maximum gain,e.g., will receive the most wireless power. As a result, no signals aresent in directions in which the wireless power receiver cannot receiver,e.g., nulls and blockages. In some embodiments, the wireless powertransmission system 501 measures the RSSI of the received beacon signaland if the beacon is less than a threshold value, the wireless powertransmission system will not send wireless power over that path.

The three paths shown in the example of FIGS. 5A and 5B are illustratedfor simplicity, it is appreciated that any number of paths can beutilized for transmitting power to the wireless device 502 depending on,among other factors, reflective and absorptive objects in the wirelesspower delivery environment.

II. Establishing Connections with WPTSs in Multi-WPTS Environments

As discussed herein, wireless power receiver clients can besimultaneously within range of multiple wireless power transmissionsystems in a wireless power delivery environment. The techniquesdiscussed herein describe techniques for establishing connections withwireless power transmission systems in multi-wireless power transmissionsystem environments.

FIG. 6 illustrates an example wireless power delivery environment 600including five wireless power transmission systems 601 a-601 e eachhaving a circular transmission range 615 a-615 e, respectively, and sixwireless power receiver clients 603 a-603 f. The circular transmissionranges 615 a-615 e are shown for simplicity; actual transmission rangescan vary depending on the individual WPTS and the environment (e.g.,based on changes in conditions, positioning of reflective objects,etc.). The transmission ranges indicate the distance to which wirelesspower can be delivery to a wireless power receiver client.

Wireless power transmission systems 601 a-601 e can be any wirelesschargers such as, for example, wireless power transmission system 101 ofFIG. 1, although alternative configurations are possible. Likewise,wireless power receiver clients 603 a-603 f can be wireless powerreceiver clients 103 of FIG. 1, although alternative configurations arepossible. As discussed herein a wireless device (not shown), e.g.,wireless device 102 of FIG. 1), can have one or more embedded, attached,and/or otherwise integrated wireless power receiver clients 603.

In the example of FIG. 6, each wireless power receiver client 603 a-f iswithin range of one or more wireless power transmission systems 601. Thetechniques described herein provide the wireless power receiver clientswith techniques for selecting an optimal wireless power transmissionsystem when wireless power receiver client is within range of more thanone wireless power transmission system. In some embodiments, the optimalwireless power transmission system can be determined based on variousselection criteria.

FIG. 7 is a flow diagram illustrating an example process 700 forestablishing RF power connections with wireless power transmissionsystems in multi-wireless power transmission system environments,according to some embodiments. More specifically, FIG. 7 illustratestechniques for determining a wireless power transmission system withwhich to connect when the multiple wireless power transmission systemsare within range. Components of a wireless power receiver client suchas, for example, wireless power receiver client 103 of FIG. 1 or 400 ofFIG. 4, can, among other functions, perform the example process 700.

To begin, at step 710, the wireless power receiver client receives anindication to enter a listen mode. In some embodiments, one or moretimers may be set such that the listen mode occurs periodically for apre-determined length of time. For example, the listen mode could occurfor a length of one to two minutes every ten to sixty minutes. In someembodiments, the length of time of the listen mode can be set up as amultiple of the amount of time between broadcasts from a wireless powertransmission system. For example, wireless power transmission systemsmay broadcast a connection invitation, e.g., a “join my network”message, at an interval of every twenty seconds. In such cases, thelength of time for operating in the listen mode can be set to between3×-6× the wireless power transmission system broadcast interval.Alternatively, or additionally, the wireless power receiver client canautomatically go into the listen mode when the received power dropsbelow a threshold, or drops below a set percentage from the previouspower (e.g. if the received power drops 20% for 60 seconds, the cliententers can be configured to enter the listen mode). At step 712, thewireless power receiver client optionally starts a listen mode timer andenters the listen mode.

At step 714, the wireless power receiver client listens for broadcastsignals transmitted by wireless power transmission systems in wirelesspower delivery environment. The broadcast signals can include connectioninvitations and/or information signaling (e.g., ‘join my network’messages). At decision step 716, if the wireless power receiver clientdetermines whether a connection invitation and/or other connectioninformation is received from a wireless power transmission system. Ifnot, at decision step 730, the wireless power receiver client determineswhether the listen mode timer has expired. If the listen mode timer hasexpired, the wireless power receiver client exits the listen modeoperation and resumes normal operations (e.g., power reception) in anormal operating mode. However, if the listen mode time has not expiredthen the process continues again at step 714.

Again referring to step 716, if the wireless power receiver clientreceives a connection invitation and/or other connection informationfrom a particular wireless power transmission system (WPTS) then, atstep 718, the wireless power receiver client determines and/or otherwiseidentifies attributes of the WPTS. As discussed herein, determiningattributes of the WPTS can include, by way of example and notlimitation, measuring a signal strength or RSSI of the signal receivedfrom the WPTS, e.g., the connection invitation, identifying a number ofother wireless power receiver clients associated with the first wirelesspower transmission system, etc. In this context, the wireless powerreceiver clients associated with the first wireless power transmissionsystem are the wireless power receiver clients that have previouslyresponded to the connection invitation. In some embodiments, thewireless power receiver client can determine the number of devicesassociated with the wireless power transmission system by, for example,receiving a message from the wireless power transmission systemproviding this information, by receiving unique beacon signals fromother clients, etc.

At step 720, the wireless power receiver client accesses attributes ofother wireless power transmission systems in the wireless power deliveryenvironment. In some embodiments, the attributes of other wireless powertransmission systems can be maintained in a wireless power rankingtable. At step 722, accesses selection criteria for determining the‘optimal’ wireless power transmission system with which to connect. Theselection criteria can include techniques, algorithms, threshold, etc.that are utilized by the wireless power receiver client to score and/orrank the wireless power transmission systems within range. For example,the selection criteria can include signal strength threshold values, thenumber of wireless power receiver clients connected to a wireless powertransmission system being above and/or below particular thresholds, etc.An example of various selection criteria is shown and discussed ingreater detail with reference to example table 1000 of FIG. 10.

At decision step 726, the wireless power receiver client determineswhether to accept the connection invitation from the WPTS. An exampleillustrating a process of determining whether to accept the connectioninvitation from the WPTS is shown and discussed in greater detail withreference to FIG. 8. If the connection invitation is accepted, then atstep 728, the wireless power receiver client establishes a connectionwith the WPTS and the process subsequently continues at decision step730. Alternatively, the process can resume normal operation after aconnection with the WPTS is established. If the connection invitation isnot accepted, then the process continues at decision step 730 withoutestablishing a new connection.

FIG. 8 is a flow diagram illustrating an example process 800 fordetermining whether to accept a connection invitation from a WPTS,according to some embodiments. More specifically, FIG. 8 illustrates anexample whereby wireless power transmission systems within range arescored and ranked to make a determination as to whether to accept aconnection invitation received from a particular WPTS. Components of awireless power receiver client such as, for example, wireless powerreceiver client 103 of FIG. 1 or 400 of FIG. 4, can, among otherfunctions, perform the example process 800.

To begin, at step 810, the wireless power receiver client generates ascore for the WPTS. An example illustrating generation of a score for aWPTS is shown and discussed in greater detail with reference to FIG. 9.At step 812, the wireless power receiver client accesses previouslygenerated scores for the other wireless power transmission systems. Asdiscussed herein, the attributes and/or scores and ranks for eachwireless power transmission system within range can be kept andmaintained by the wireless power receiver client.

At step 814, the wireless power receiver client ranks the wireless powertransmissions systems based on the scores and, at decision step 816, thewireless power receiver client determines if the newly ranked wirelesspower transmission system (i.e., the wireless power transmission systemwhich sent the invitation) is greater than the rank of the currenthighest ranking wireless power transmission system (assuming that thereis at least one current wireless power transmission system ranking). Ifthe newly ranked wireless power transmission system is higher than thecurrent highest ranking wireless power transmission system, then thewireless power receiver client makes a determination to accept theconnection invitation at step 818. Alternatively, if the newly rankedwireless power transmission system is not higher than the currenthighest ranking wireless power transmission system, then the wirelesspower receiver client makes a determination to not to accept theconnection invitation at step 820.

FIG. 9 is a flow diagram illustrating an example process 900 of scoringwireless power transmission systems within range, according to someembodiments. As discussed herein the scores can be used to identifyand/or otherwise determine the optimal wireless power transmissionsystem with which to connect when a client is within range of multiplewireless power transmission systems. Components of a wireless powerreceiver client such as, for example, wireless power receiver client 103of FIG. 1 or 400 of FIG. 4, can, among other functions, perform theexample process 900.

To begin, at step 910, the wireless power receiver client measures thesignal strength of the signal received from the wireless powertransmission system. At process 912, the wireless power receiver clientdetermines the number of devices associated with the wireless powertransmission system, e.g. by receiving a message from the wireless powertransmission system providing this information, or by receiving uniquebeacon signals from other clients. At process 914, the wireless powerreceiver client identifies client classification information. At process916, the wireless power client optionally applies classification weightsto the criteria. Lastly, at process 918, the wireless power receiverclient ranks the wireless power transmission systems based on theweighted criteria.

FIG. 10 is an example table 1000 illustrating various wireless powertransmission system selection criteria, according to some embodiments.Additional or fewer criteria are possible. As illustrated in the exampleof FIG. 10, in some embodiments, the criteria can have accompanyingweights. As shown, a client may have a low power usage classification(e.g. a smoke alarm) and, thus, receive a low weight, while another mayhave a high classification (e.g. a laptop, or a laptop with less than20% of remaining battery), and, thus, receive a high weight. Anothercriteria may be the number of devices. Thus, if a wireless powertransmission system is already burdened with large number of devices,another wireless power transmission system may be selected.

FIG. 11 is a flow diagram illustrating another example process 1100 forestablishing connections with continuous power delivery wirelesscharging systems, according to some embodiments. The steps of FIG. 11are generally self-explanatory and, thus, not discussed in greaterdetail here. As discussed herein, the “Join network invitation” is aspecial broadcast message transmitted from a wireless power transmissionsystem to one or more clients inviting the clients to join the wirelesspower transmission system's network. The decision step, “Is presentinvitation from preferred wireless power transmission system?” generallychecks if the presently received invitation is from the network theclient wants to join.

FIG. 12 depicts a block diagram illustrating example components of arepresentative mobile device or tablet computer 1200 with a wirelesspower receiver or client in the form of a mobile (or smart) phone ortablet computer device, according to some embodiments. Variousinterfaces and modules are shown with reference to FIG. 12, however, themobile device or tablet computer does not require all of modules orfunctions for performing the functionality described herein. It isappreciated that, in many embodiments, various components are notincluded and/or necessary for operation of the category controller. Forexample, components such as GPS radios, cellular radios, andaccelerometers may not be included in the controllers to reduce costsand/or complexity. Additionally, components such as ZigBee radios andRFID transceivers, along with antennas, can populate the Printed CircuitBoard.

The wireless power receiver client can be a power receiver client 103 ofFIG. 1, although alternative configurations are possible. Additionally,the wireless power receiver client can include one or more RF antennasfor reception of power and/or data signals from a power transmissionsystem, e.g., wireless power transmission system 101 of FIG. 1.

FIG. 13 depicts a diagrammatic representation of a machine, in theexample form, of a computer system within which a set of instructions,for causing the machine to perform any one or more of the methodologiesdiscussed herein, may be executed.

In the example of FIG. 13, the computer system includes a processor,memory, non-volatile memory, and an interface device. Various commoncomponents (e.g., cache memory) are omitted for illustrative simplicity.The computer system 1300 is intended to illustrate a hardware device onwhich any of the components depicted in the example of FIG. 1 (and anyother components described in this specification) can be implemented.For example, the computer system can be any radiating object or antennaarray system. The computer system can be of any applicable known orconvenient type. The components of the computer system can be coupledtogether via a bus or through some other known or convenient device.

The processor may be, for example, a conventional microprocessor such asan Intel Pentium microprocessor or Motorola power PC microprocessor. Oneof skill in the relevant art will recognize that the terms“machine-readable (storage) medium” or “computer-readable (storage)medium” include any type of device that is accessible by the processor.

The memory is coupled to the processor by, for example, a bus. Thememory can include, by way of example but not limitation, random accessmemory (RAM), such as dynamic RAM (DRAM) and static RAM (SRAM). Thememory can be local, remote, or distributed.

The bus also couples the processor to the non-volatile memory and driveunit. The non-volatile memory is often a magnetic floppy or hard disk, amagnetic-optical disk, an optical disk, a read-only memory (ROM), suchas a CD-ROM, EPROM, or EEPROM, a magnetic or optical card, or anotherform of storage for large amounts of data. Some of this data is oftenwritten, by a direct memory access process, into memory during executionof software in the computer 1300. The non-volatile storage can be local,remote, or distributed. The non-volatile memory is optional becausesystems can be created with all applicable data available in memory. Atypical computer system will usually include at least a processor,memory, and a device (e.g., a bus) coupling the memory to the processor.

Software is typically stored in the non-volatile memory and/or the driveunit. Indeed, for large programs, it may not even be possible to storethe entire program in the memory. Nevertheless, it should be understoodthat for software to run, if necessary, it is moved to a computerreadable location appropriate for processing, and for illustrativepurposes, that location is referred to as the memory in this paper. Evenwhen software is moved to the memory for execution, the processor willtypically make use of hardware registers to store values associated withthe software, and local cache that, ideally, serves to speed upexecution. As used herein, a software program is assumed to be stored atany known or convenient location (from non-volatile storage to hardwareregisters) when the software program is referred to as “implemented in acomputer-readable medium”. A processor is considered to be “configuredto execute a program” when at least one value associated with theprogram is stored in a register readable by the processor.

The bus also couples the processor to the network interface device. Theinterface can include one or more of a modem or network interface. Itwill be appreciated that a modem or network interface can be consideredto be part of the computer system. The interface can include an analogmodem, isdn modem, cable modem, token ring interface, satellitetransmission interface (e.g. “direct PC”), or other interfaces forcoupling a computer system to other computer systems. The interface caninclude one or more input and/or output devices. The I/O devices caninclude, by way of example but not limitation, a keyboard, a mouse orother pointing device, disk drives, printers, a scanner, and other inputand/or output devices, including a display device. The display devicecan include, by way of example but not limitation, a cathode ray tube(CRT), liquid crystal display (LCD), or some other applicable known orconvenient display device. For simplicity, it is assumed thatcontrollers of any devices not depicted in the example of FIG. 13 residein the interface.

In operation, the computer system 1300 can be controlled by operatingsystem software that includes a file management system, such as a diskoperating system. One example of operating system software withassociated file management system software is the family of operatingsystems known as Windows® from Microsoft Corporation of Redmond, Wash.,and their associated file management systems. Another example ofoperating system software with its associated file management systemsoftware is the Linux operating system and its associated filemanagement system. The file management system is typically stored in thenon-volatile memory and/or drive unit and causes the processor toexecute the various acts required by the operating system to input andoutput data and to store data in the memory, including storing files onthe non-volatile memory and/or drive unit.

Some portions of the detailed description may be presented in terms ofalgorithms and symbolic representations of operations on data bitswithin a computer memory. These algorithmic descriptions andrepresentations are the means used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of operations leading to adesired result. The operations are those requiring physicalmanipulations of physical quantities. Usually, though not necessarily,these quantities take the form of electrical or magnetic signals capableof being stored, transferred, combined, compared, and otherwisemanipulated. It has proven convenient at times, principally for reasonsof common usage, to refer to these signals as bits, values, elements,symbols, characters, terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise, as apparent from the followingdiscussion, it is appreciated that throughout the description,discussions utilizing terms such as “processing” or “computing” or“calculating” or “determining” or “displaying” or the like, refer to theaction and processes of a computer system, or similar electroniccomputing device, that manipulates and transforms data represented asphysical (electronic) quantities within the computer system's registersand memories into other data similarly represented as physicalquantities within the computer system memories or registers or othersuch information storage, transmission or display devices.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general purposesystems may be used with programs in accordance with the teachingsherein, or it may prove convenient to construct more specializedapparatus to perform the methods of some embodiments. The requiredstructure for a variety of these systems will appear from thedescription below. In addition, the techniques are not described withreference to any particular programming language, and variousembodiments may thus be implemented using a variety of programminglanguages.

In alternative embodiments, the machine operates as a standalone deviceor may be connected (e.g., networked) to other machines. In a networkeddeployment, the machine may operate in the capacity of a server or aclient machine in a client-server network environment or as a peermachine in a peer-to-peer (or distributed) network environment.

The machine may be a server computer, a client computer, a personalcomputer (PC), a tablet PC, a laptop computer, a set-top box (STB), apersonal digital assistant (PDA), a cellular telephone, an iPhone, aBlackberry, a processor, a telephone, a web appliance, a network router,switch or bridge, or any machine capable of executing a set ofinstructions (sequential or otherwise) that specify actions to be takenby that machine.

While the machine-readable medium or machine-readable storage medium isshown in an exemplary embodiment to be a single medium, the term“machine-readable medium” and “machine-readable storage medium” shouldbe taken to include a single medium or multiple media (e.g., acentralized or distributed database, and/or associated caches andservers) that store the one or more sets of instructions. The term“machine-readable medium” and “machine-readable storage medium” shallalso be taken to include any medium that is capable of storing, encodingor carrying a set of instructions for execution by the machine and thatcause the machine to perform any one or more of the methodologies of thepresently disclosed technique and innovation.

In general, the routines executed to implement the embodiments of thedisclosure, may be implemented as part of an operating system or aspecific application, component, program, object, module or sequence ofinstructions referred to as “computer programs.” The computer programstypically comprise one or more instructions set at various times invarious memory and storage devices in a computer, and that, when readand executed by one or more processing units or processors in acomputer, cause the computer to perform operations to execute elementsinvolving the various aspects of the disclosure.

Moreover, while embodiments have been described in the context of fullyfunctioning computers and computer systems, those skilled in the artwill appreciate that the various embodiments are capable of beingdistributed as a program product in a variety of forms, and that thedisclosure applies equally regardless of the particular type of machineor computer-readable media used to actually effect the distribution.

Further examples of machine-readable storage media, machine-readablemedia, or computer-readable (storage) media include but are not limitedto recordable type media such as volatile and non-volatile memorydevices, floppy and other removable disks, hard disk drives, opticaldisks (e.g., Compact Disk Read-Only Memory (CD ROMS), Digital VersatileDisks, (DVDs), etc.), among others, and transmission type media such asdigital and analog communication links.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof, means any connection or coupling,either direct or indirect, between two or more elements; the coupling ofconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, shall referto this application as a whole and not to any particular portions ofthis application. Where the context permits, words in the above DetailedDescription using the singular or plural number may also include theplural or singular number respectively. The word “or,” in reference to alist of two or more items, covers all of the following interpretationsof the word: any of the items in the list, all of the items in the list,and any combination of the items in the list.

The above detailed description of embodiments of the disclosure is notintended to be exhaustive or to limit the teachings to the precise formdisclosed above. While specific embodiments of, and examples for, thedisclosure are described above for illustrative purposes, variousequivalent modifications are possible within the scope of thedisclosure, as those skilled in the relevant art will recognize. Forexample, while processes or blocks are presented in a given order,alternative embodiments may perform routines having steps, or employsystems having blocks, in a different order, and some processes orblocks may be deleted, moved, added, subdivided, combined, and/ormodified to provide alternative or subcombinations. Each of theseprocesses or blocks may be implemented in a variety of different ways.Also, while processes or blocks are, at times, shown as being performedin a series, these processes or blocks may instead be performed inparallel, or may be performed at different times. Further, any specificnumbers noted herein are only examples: alternative implementations mayemploy differing values or ranges.

The teachings of the disclosure provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments.

Any patents and applications and other references noted above, includingany that may be listed in accompanying filing papers, are incorporatedherein by reference. Aspects of the disclosure can be modified, ifnecessary, to employ the systems, functions, and concepts of the variousreferences described above to provide yet further embodiments of thedisclosure.

These and other changes can be made to the disclosure in light of theabove Detailed Description. While the above description describescertain embodiments of the disclosure, and describes the best modecontemplated, no matter how detailed the above appears in text, theteachings can be practiced in many ways. Details of the system may varyconsiderably in its implementation details, while still beingencompassed by the subject matter disclosed herein. As noted above,particular terminology used when describing certain features or aspectsof the disclosure should not be taken to imply that the terminology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the disclosure with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the disclosure to the specific embodimentsdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe disclosure encompasses not only the disclosed embodiments, but alsoall equivalent ways of practicing or implementing the disclosure underthe claims.

While certain aspects of the disclosure are presented below in certainclaim forms, the inventors contemplate the various aspects of thedisclosure in any number of claim forms. For example, while only oneaspect of the disclosure is recited as a means-plus-function claim under35 U.S.C. § 112, ¶16, other aspects may likewise be embodied as ameans-plus-function claim, or in other forms, such as being embodied ina computer-readable medium. (Any claims intended to be treated under 35U.S.C. § 112, ¶16 will begin with the words “means for”.) Accordingly,the applicant reserves the right to add additional claims after filingthe application to pursue such additional claim forms for other aspectsof the disclosure.

The detailed description provided herein may be applied to othersystems, not necessarily only the system described above. The elementsand acts of the various examples described above can be combined toprovide further implementations of the invention. Some alternativeimplementations of the invention may include not only additionalelements to those implementations noted above, but also may includefewer elements. These and other changes can be made to the invention inlight of the above Detailed Description. While the above descriptiondefines certain examples of the invention, and describes the best modecontemplated, no matter how detailed the above appears in text, theinvention can be practiced in many ways. Details of the system may varyconsiderably in its specific implementation, while still beingencompassed by the invention disclosed herein. As noted above,particular terminology used when describing certain features or aspectsof the invention should not be taken to imply that the terminology isbeing redefined herein to be restricted to any specific characteristics,features, or aspects of the invention with which that terminology isassociated. In general, the terms used in the following claims shouldnot be construed to limit the invention to the specific examplesdisclosed in the specification, unless the above Detailed Descriptionsection explicitly defines such terms. Accordingly, the actual scope ofthe invention encompasses not only the disclosed examples, but also allequivalent ways of practicing or implementing the invention.

What is claimed is:
 1. A method of operating a wireless power receiverapparatus to establish a connection with a wireless power transmissionsystem in a wireless power delivery environment, the method comprising:receiving a connection invitation transmitted by a first wireless powertransmission system of multiple wireless power transmission systems inthe wireless power delivery environment; processing the connectioninvitation to identify attributes associated with the first wirelesspower transmission system; applying selection criteria to the attributesassociated with the first wireless power transmission system andattributes associated with other wireless power transmission systems ofthe multiple wireless power transmission systems in the wireless powerdelivery environment to determine whether to accept the connectioninvitation.
 2. The method of claim 1, wherein applying the selectioncriteria further comprises: generating a score for the first wirelesspower transmission system.
 3. The method of claim 2, wherein generatingthe score further comprises: identifying a client classificationassociated with a wireless device in which the wireless power receiverapparatus is embedded, wherein the client classification indicates oneor more classification weights associated with each attribute; andapplying the classification weights to the attributes associated withthe first wireless power transmission system.
 4. The method of claim 2,wherein applying the selection criteria further comprises: accessingscores for the other wireless power transmission systems of the multiplewireless power transmission systems; and ranking the wireless powertransmission systems according to the corresponding scores.
 5. Themethod of claim 4, wherein applying the selection criteria furthercomprises: making a determination to accept the connection invitation ifthe first wireless power transmission system is ranked higher than acurrent wireless power transmission system; and making a determinationnot to accept the connection invitation if the first wireless powertransmission system is ranked lower than a current wireless powertransmission system.
 6. The method of claim 1, wherein processing theconnection invitation to identify attributes associated with the firstwireless power transmission system further comprises: measuring a signalstrength of the connection invitation.
 7. The method of claim 1, whereinprocessing the connection invitation to identify attributes associatedwith the first wireless power transmission system further comprises:identifying a number of other wireless power receiver clients associatedwith the first wireless power transmission system.
 8. The method ofclaim 1, further comprising: accessing the selection criteria, theselection criteria indicating one or more thresholds for each of the oneor more of the attributes; accessing attributes associated with otherwireless power transmission systems of the multiple wireless powertransmission systems in the wireless power delivery environment;
 9. Themethod of claim 1, further comprising: prior to receiving the connectioninvitation, receiving an indication to enter an invitation listen modeand responsively entering the listen mode and commencing a listen modetimer.
 10. The method of claim 1, wherein the connection invitation isbroadcast periodically by one or more of the multiple wireless powertransmission system to wireless power receiver apparatuses in thewireless power delivery environment.
 11. The method of claim 1, furthercomprising: periodically directing one or more antennas of the wirelesspower receiver apparatus or a wireless device in which the wirelesspower receiver apparatus is embedded to listen for the broadcastconnection invitation messages transmitted by the wireless powertransmission systems;
 12. The method of claim 1, further comprising:directing one or more transceivers of the wireless power receiverapparatus or a wireless device in which the wireless power receiverapparatus is embedded to transmit a response to the connectioninvitation message, wherein the response indicates an acceptance of theconnection invitation message.
 13. The method of claim 11, furthercomprising: establishing a wireless power connection with the firstwireless power delivery system subsequent to transmitting the responseto the connection invitation message.
 14. A computer readable storagemedium having program instructions stored thereon which, when executedby one or more processors of a wireless power receiver apparatus, causethe wireless power receiver apparatus to: process a connectioninvitation request transmitted by a first wireless power transmissionsystem of multiple wireless power transmission systems in the wirelesspower delivery environment to identify attributes associated with thefirst wireless power transmission system; and apply selection criteriato the attributes associated with the first wireless power transmissionsystem and attributes associated with other wireless power transmissionsystems of the multiple wireless power transmission systems in thewireless power delivery environment to determine whether to accept theconnection invitation.
 15. The computer readable storage medium of claim14, wherein to apply the selection criteria, the instructions, whenexecuted by the one or more processors, further cause the wireless powerreceiver apparatus to: generate a score for the first wireless powertransmission system; access scores for the other wireless powertransmission systems of the multiple wireless power transmissionsystems; and rank the wireless power transmission systems according tothe corresponding scores.
 16. The computer readable storage medium ofclaim 15, wherein to generate the score, the instructions, when executedby the one or more processors, further cause the wireless power receiverapparatus to: identify a client classification associated with awireless device in which the wireless power receiver apparatus isembedded, wherein the client classification indicates one or moreclassification weights associated with each attribute; and apply theclassification weights to the attributes associated with the firstwireless power transmission system.
 17. The computer readable storagemedium of claim 15, wherein to apply the selection criteria, theinstructions, when executed by the one or more processors, further causethe wireless power receiver apparatus to: accept the connectioninvitation if the first wireless power transmission system is rankedhigher than a current wireless power transmission system; and not acceptthe connection invitation if the first wireless power transmissionsystem is ranked lower than a current wireless power transmissionsystem.
 18. The computer readable storage medium of claim 14, wherein toprocess the connection invitation to identify attributes associated withthe first wireless power transmission system, the instructions, whenexecuted by the one or more processors, further cause the wireless powerreceiver apparatus to: measuring a signal strength of the connectioninvitation; and identify a number of other wireless power receiverclients associated with the first wireless power transmission system.19. The computer readable storage medium of claim 14, wherein theinstructions, when executed by the one or more processors, further causethe wireless power receiver apparatus to: directing one or moretransceivers of the wireless power receiver apparatus or a wirelessdevice in which the wireless power receiver apparatus is embedded totransmit a response to the connection invitation message, wherein theresponse indicates an acceptance of the connection invitation message;and establish a wireless power connection with the first wireless powerdelivery system subsequent to transmitting the response to theconnection invitation message.
 20. A wireless power receiver apparatuscomprising: one or more radio frequency (RF) transceivers; controlcircuitry configured to direct the one or more RF transceivers toestablish a connection with a first wireless power transmission systemof multiple wireless power transmission systems in a wireless powerdelivery environment, the control circuitry including: listen modereception logic configured to receive, via the one or more RFtransceivers, a connection invitation transmitted by the first wirelesspower transmission system and responsive process the connectioninvitation to identify attributes associated with the first wirelesspower transmission system; wireless power transmission selection logicconfigured to apply selection criteria to the attributes associated withthe first wireless power transmission system and attributes associatedwith other wireless power transmission systems of the multiple wirelesspower transmission systems in the wireless power delivery environment todetermine whether to accept the connection invitation, wherein theselection criteria indicates one or more threshold values for eachattribute.